#define _CRT_SECURE_NO_WARNINGS 1
class Date {
public:
	Date(int year = 0, int month = 1, int day = 1) {
		_year = year;
		_month = month;
		_day = day;
	}

	/* Date d2(d1); */
	Date(const Date& d) {    // 如果内部不需要改变，建议加上const
		_year = d._year;
		_month = d._month;
		_day = d._day;
	}

	void Print() {
		printf("%d-%d-%d\n", _year, _month, _day);
	}

private:
	int _year;
	int _month;
	int _day;
};